Sensei
by DarkPheonix 666
Summary: Saitama becomes troubled by how Genos always calls her Sensei when they have sex. Wanting to get rid of the problem she asks Genos to call her something else. However this causes Genos to do something she never expected. YURI, Lesbian, Female Saitama, Female Genos, SAIGENOS, genderbend, Rule 63, Eventual smut
1. Chapter 1

**I was inspired to write this after reading a Yaoi doujin of the same premise**

 **However I went rule 63 and genderbent Saitama and Genos causing me to alter the story a little**

 **I also feel like there isn't a lot of SaiGenos Yuri out there**

 **Please review, follow and favourite**

 **Darkpheonix666**

Saitama sighed heavily and pointed her finger accusingly at Genos. This had been bothering her for a while and now she was finally going to confront the problem. If she left it alone things would only get worse.

"Genos; from now on you are forbidden from calling me Sensei" she said sharply. She knew this was going to be hard on her but it was necessary. If things continued the way they were she would only get unwanted attention.

Genos stiffened and her face became a look of horror. She dropped the pot she was cleaning which landed on the floor with a loud clang. She had thought something was wrong with Saitama for a while but she had never addressed it.

She now felt so foolish for not going with her instinct and leaving things be. Now her sensei was angry at her but there was nothing she could do about it. However she would try and make amends for whatever she had done.

Saitama winced at the sound of the pot being dropped but didn't mind it. I mean it was made out of metal so it wasn't really breakable. However she was worried about if it may have dented or cracked the floor.

Genos then slammed her hands down onto the floor and curled up into a bowing position; her head cracking the floor a little. "I'm sorry Sensei! Please forgive me for upsetting you" she cried apologetically.

She had tried to be useful to Saitama, to be polite to her and help her as an apprentice. But she had seemingly done nothing but get in her way. She would never forgive herself for causing Saitama trouble.

Saitama was rather stunned by Genos's reaction and blinked in awe. She really hadn't expected Genos to react in such a manner. I mean she was used to her being high maintenance but this was a little over the top.

She laughed nervously and scratched her face awkwardly "It's…It's not really a serious problem Genos" she explained casually. When unless you counted the fact that she felt like a pervert. Yes, though she didn't show it Saitama had a conscience that made her self-aware.

Genos was relieved to hear such a thing. But was upset that Saitama would confuse her like this; it was not helping her system one bit. She was not as good at understanding humans especially Saitama.

She sat up quietly and folded her arms crossly; her amber eyes filled with displeasure "Please don't make such inappropriate jokes sensei" she said firmly. She had been very effected by her words.

She was used to her sensei making bad or light humored jokes. Not cruel ones that messed with her systems and caused her to panic. She had feared that Saitama may throw her out.

Saitama sighed heavily once more; it seemed that Genos still didn't get what she was talking about after all. "I wasn't joking Genos" she replied dryly. While she did care for the young cyborg; this was a serious matter that needed addressing.

Genos sat down on her knees before Saitama at the table. She would need to be seated in order to fully understand what the hell was going on. While she found Saitama hard to understand; today was more difficult than usual.

She looked at Saitama her eyes filled with confusion but her face calm yet conflicted. You could hear the gears whirring in her head as she thought. She was using all her systems to try and figure out what was going on. What the hell was happening and why?

Saitama relaxed and became thoughtful; this was more awkward to explain that she expected it to be. She really wasn't happy about this one bit. She wasn't really used to talking about this kind of subject.

While she was a laid back, casual and indifferent person; she was still human and had some feelings she could still express. "Well…you are still my trainee and that means you are my disciple…" Saitama explained her tone wavering.

Genos was indeed working under her and learning all she could about becoming a strong hero. She was doing well and learning good moral codes; but she still seemed to feel imperfect.

Genos gripped her hands into fists; the waiting was making her systems act up and her core was pulsing in her chest. She believed this was what humans called nervousness?

Saitama relented and looked her dead in the eye "When we have sex you call me Sensei too. I do have neighbours and they will think I'm a pervert or something like that" she explained awkwardly.

Saitama didn't care what people thought about her in the slightest. But she was cautious of how her actions effected other people. One of the biggest assets of being a hero was being aware of how your actions effected others.

She could only imagine what her neighbours would be thinking when they heard a younger female voice crying out "Sensei" at god knows what time of the night or day. Hell sometimes there were little kids playing in the nearby areas.

"People are going to think I'm a cougar or some form of dirty older woman who has a thing for teenagers" she explained hesitantly. She already got enough trouble as it was from losers who sent her spam mail for being a faker.

She got attacked by the odd pervert while out or people staring at her breasts. The last thing she needed was people thinking she was some form of pervert who had a teacher kink.

She was aware some people had a kink for that and even watched Porno of it. But she was not one of those people and didn't want people getting the wrong idea of it. She didn't like being accused of things she didn't do.

Genos frowned and tilted her head a little "But you are my sensei and thus I must call you as such. What else would I call you?" she replied abruptly. She was only being respectful and speaking honestly.

She realized her tone came across as impatient or rude; but she couldn't help herself. She didn't understand what was going on at all. Her systems were not giving her sustainable answer to the situation.

Saitama hummed thoughtfully and leaned back a little staring at the ceiling. She wracked her brain of a good nickname before she found the right one. She had always wanted a nickname; even as a kid.

She smiled playfully and looked at Genos "How about Sai? Or Sai-chan?" she suggested. I mean it was a shortened version of her name. Plus it did sound just a little cuter like one of those Yuri comics Genos would sometimes read.

She knew Genos was just trying to be respectful but she had told her name when they first met. It would be nice if she could use it just once. She hadn't heard someone call her name since she was in college or school.

Genos displayed a look of disgust and shame upon hearing it. It just didn't feel right and she felt like she was being dishonorable. "No Sensei I cannot. I am merely your student and that is all. To call you anything else would be rude" she retorted defiantly.

She would stand by her decision even if it upset Saitama; which she knew it did. She hated that she was going against her sensei but she couldn't bring herself to say anything but that word.

To address Saitama as anything but Sensei just made her feel like she was insulting the woman. Like she was taking away Saitama's honour in some way. And as a Hero she could not allow herself to do something like that.

Saitama groaned wearily and tilted her body back against the futon pile. She was getting nowhere with this and she was right back to where she started. They were just going round in circles.

Genos was a highly stubborn individual and it often caused more problems than most. This meant she would stand by her decision no matter what. It was both a problematic and useful personality trait to have.

Suddenly that was when it hit her. She knew it was cruel but it was the only way she could think of to fix this problem. Plus, it would end the rumours that any of her neighbours may start.

She then pointed her finger at Genos again her expression solemn. She was going to have to be serious for this in order for the message to get across. Otherwise it would not sink into Genos's system.

"Genos. From now on you are banned from calling me Sensei when we have sex. Do you understand?" she said sharply. That way Genos call her by her first name; she had no other option. Plus She would feel less like a pervert who was doing something wrong.

Meanwhile Genos had gone quiet and simply nodded in understanding. If this was what her sensei wished then she would obey her demands no matter what. She would do whatever she wished if it made Saitama happy.

Content with clearing their problems; Saitama stretched and sighed in relief. She felt a few bones in her back crack making her feel comfortable. You'd never think that sitting down would cause so much aches in your body.

"I'm going to take a nap for a while. But wake me up in a while so we can go shopping ok?" she said casually. There was going to be a discount sale on noodles and pork. She had been wanting to make ramen for a while now.

It was getting chilly and she fancied something warm in order to fill her belly and keep out the cold. Ramen would hit the spot pretty well too. Plus she hadn't eaten it since her student years and it would be nostalgic.

Genos nodded quietly but didn't move. Her head was bowed causing her blonde hair to tumble over her shoulders a little. She was trying to hide her unhappiness and conflict from Saitama.

She wasn't very happy about being unable to say her sensei's name anymore. But if it would bring her relief she would follow through with her demands. She would try her hardest to remain quit during their intimacy.

"I must control myself from now on. If that is what my sensei wishes of me" she thought to herself quietly. She was already causing Saitama enough conveniences as it was; she did not wish to cause her any more.


	2. C2: Do what you want

**Genos tries to keep her mouth during sex and fails**

 **Fluff and humor**

Loud moans and gasps filled the room as the two heroines were wrapped in each other's arms. Sounds of pleasure and desire escaping their lips as their need for each other grew stronger. The smell of sweat and sex filling the room, proof of the deep passion being shared between the two women.

Saitama was licking Genos's ear and had her back pressed against the metallic frame of Genos's torso. It was smooth and cold against her skin but felt really good against her chest. Her fingers were pumping in and out of Genos's groin. Instead of where a female flesh should have been; instead was a black rubber mould that was very similar to the real thing.

Genos had her head bowed low towards the floor, her cheeks flushed with want and embarrassment. Her long blonde hair falling down her shoulders and face hiding her expression. Her fingers tightly grasping the sheets and biting her lip hard. If she was a human it would no doubt be bleeding by now with the amount of pressure she had on it.

But everything felt so good and Saitama was really skilled with her fingers. She had obviously done this sort of thing before and Genos wondered if she had experimented in college. Saitama was very quiet about her personal life and past, however Genos was no idiot. She could quite clearly tell that Saitama had experience in this field.

" _S…Sensei's fingers…. feel so good. But…I…I have to stay quiet. Or…Or Sensei will…."_ Genos thought to herself mentally. She knew how much trouble she was causing the heroine already. If she made any more noise during their intimate time the landlord and neighbours would only complain. And Saitama was very concerned with respecting the peace and quiet of others.

Saitama then roamed her hands upwards across Genos's abdomen and cupped her breast plates. They were half made of metal and rubber; giving them a realistic appearance. They weren't too small and not too big; fitting well in Saitama's hands. There were even small bumps to imitate nipples which often impressed Saitama at the doctor's skill.

Genos jolted and arched her back as Saitama's hands roamed over her chest. She wanted to cry out so badly but for her sensei she would stay quiet to make her happy. She refused to let herself make any noise, she would keep her voice locked away until the very end just like she was asked to.

Saitama sighed heavily under her breath making sure Genos wouldn't hear her. For some reason, Genos wasn't making her cute voice but was indeed reacting well to her touch. She would be lying if she said she wasn't somewhat confused at why Genos was acting this way.

She then flipped Genos over before the cyborg could process what happened. There was a soft cry from the blonde that made Saitama shiver with joy upon hearing it. Though she did worry about what kinds of things Genos would say during sex, her cute moans were something she enjoyed hearing.

Genos was a seriously cute girl; even if she wasn't human. Her baby face, soft blonde locks and golden irises in the middle of her black metallic eyes. She really was lucky to have such a girl in her life even if she could be annoying sometimes.

She leaned forward to lick Genos's face affectionately lapping up the small forming tears in her eyes. She tasted really good, salty and somewhat metallic from her cyborg body. The girl beneath her shivering at the contact of Saitama's tongue against her soft skin, goosebumps running across her metallic skin.

Saitama began to slowly hump Genos's leg rubbing herself against the cyborg. Her fluids running down the metal of Genos's leg as she did so. Her own needs being met while getting Genos off. "Say Genos? Why so quiet today hmm?" Saitama panted heavily she continued to move. Usually she was a lot more vocal than this during sex, it felt rather odd to see her being the opposite.

Genos jolted upon hearing Saitama call out her name. This wasn't fair at all, she wanted to say Saitama's name too but she couldn't or she would upset Saitama again. "S…Sensei!" she gasped suddenly. She then slapped a hand over her mouth quickly realizing what she had done. Saitama had ordered her not to yet she had broken her promise.

She then began to panic internally and looked away from the older female nervously. She was in for it now, Saitama would be so mad at her for using that name again. Even though she had made it clear she no longer wanted Genos to call her by that name anymore. But she couldn't help it, it had become a habit by now.

" _I said it. Even though she asked me not to I used that name. Now Sensei will not want to be with me anymore!"_ she mentally panicked. How could she have disobeyed Saitama like that? She would be so angry at her for doing so, what if she never wanted to have sex with her ever again?

Saitama stopped moving and stared down at the cyborg silently. Her brownish red eyes filled with surprise and concern upon Genos speaking those words. So that was why Genos wasn't calling out today, she was thinking about their conversation earlier. The blonde did tend to take most of her words to heart more often than not.

She reached out a hand to caress Genos's cheek affectionately "Genos? Are you not making any sounds because of what I said at breakfast today?" she asked curiously. She wasn't mad at her, not at all. In fact she was more surprised at how much self restraint the cyborg had. As she knew how much she loved to call out her name.

Saitama was aware of how much Genos adored and respected her. She would do anything to please Saitama and make her happy; even if it meant she suffered for it in some way. The idea of upsetting the older female even unintentionally would make her break down.

She then buried her fingers deeper inside the blonde and hit a spot that was in the similar place as the human female body. The one that would drive any girl crazy and send them to cloud 9. I mean it would be pretty odd if she didn't know about such a place after going through puberty and all.

Genos cried out suddenly her head snapping back and her eyes widening to their fullest. Saitama's fingers had reached the special spot inside a woman that would drive them crazy. It felt so good, Saitama's fingers were so long and fit all the way inside, she had even trimmed her nails despite the fact that she wasn't human.

Upon seeing Genos's reaction Saitama kept moving and made sure to hit that spot over and over. Making sure that Genos was fully enjoying herself and not thinking about anything else. She then reached forward and kissed Genos's cheek as the cyborg cried out pleasant moans over and over. "Good girl Genos. Such a good girl" she cooed affectionately.

Genos then tightened around her fingers as a reaction to her praise. The compliments and praises she was receiving from her sensei only making her happier and more sensitive. It was a known fact that all people loved to be praised when having sex, being reassured that they were doing a good job or making their lover happy by satisfying them.

Genos gripped Saitama's shoulders tightly her will breaking. This wasn't fair, Saitama shouldn't be the only one allowed to call out her lover's name at a time like this. Tears then started pouring down her cheeks and she looked up at Saitama pouting slightly. "I…I can't Sensei! I want to say your name too!" she cried tearfully.

Saitama felt her face turn red as a tomato and her body grow warm. That was a dirty trick of Genos's to say such a thing this far along. Her face right now was too cute for her to handle. As if Genos wasn't already cute as it was in daily life. Now as they were making love she was even cuter, her face flushed and her breaths fast and heavy.

Saitama then pounced on the younger girl ready to capture her lips in another kiss. The fire inside her fueled and burning wildly, ready to go another few rounds until they could no longer move. Until both of them were hot shaking messes and their legs had the inability to carry their body weight from being so exhausted.

"SAY WHATEVER YOU WANT DAMN IT!" Saitama growled impatiently her eyes gleaming with desire. Fuck the neighbours, if they had a problem they could go elsewhere. As if she could say no to Genos's cute face at a time like this. Nobody would be able to say no if their lover said such a thing in the middle of having sex.

Genos gripped Saitama's soft bald mound as the older female played with her chest affectionately with her tongue. Her hand returning to its position between her legs. Her voice calling out over and over again for her beloved Sensei, the person she loved and admired more than anything.

Saitama's cheeks were red as ever, blood rushing through her body. How Genos learned to say such cute things was beyond her (from a Manga possibly?). Using it a such a crucial time was dirty play at its best, knowing Saitama wouldn't be able to say no to her.

Genos then screamed at the top of her voice as she reached her peak. Her cheeks flushing at she felt her body grow stiff and heavy. Saitama's legs clenched as she herself came and then collapsed on Genos' chest plate her mind hazy and body weak.

* * *

Saitama and Genos were laid under the blanket resting on their shared futon. Their bodies still naked but covered by the sheets for dignity and comfort. Bodies warm and still sweaty from before. They would need to bathe later and change the sheets from their mess. But that could be dealt with later. Now they were just relaxing and enjoying the moment.

Saitama was fingering Genos's messy blonde locks affectionately and resting her head upon her own pillow. Even after doing the do, it was still as soft as ever. She loved playing with Genos's hair, bringing out her affectionate and girly side just a little. Something she hadn't done since her middle school years.

"Genos. Do you think you can stop calling me Sensei? It's kind of embarrassing?" Saitama asked curiously her tone weary. She could only imagine what the neighbours would be thinking. She would have a lot of explaining to do later on when this was all over. God, that would be awkward as hell.

Genos blinked innocently and shook her head "I don't think I can Sensei" she said apologetically. Saitama was her teacher and helping her grow stronger, thus she was her Sensei. To call her anything else would be odd and just unusual, plus it felt like she would be disrespecting the older woman just a little.

Saitama sighed heavily still playing with the cyborgs hair affectionately "Your usually so quiet. But when we do it your so loud and clingy" she said thoughtfully. It was funny how Genos did a complete 180 when they had sex. It was like she was a completely different person altogether.

Not that she minded of course, but the neighbours would. "Do you think you can call me something else? Maybe my name?" Saitama asked hopefully. She didn't mind if she had to shorten it, anything other than Sensei would be great.

Genos hummed thoughtfully and searched her memory database for an alternate word. She then came up with one she believed Saitama may agree with instead. "How about Mistress?" Genos suggested casually. It wasn't Sensei so she doubted Saitama could disagree. Plus, she would still be showing respect to her master.

Saitama slumped her head into the pillows just couldn't win, no matter how hard she tried. That was even worse than her using Sensei "Never mind" she muttered weakly. There was just no way she could win either way.


End file.
